Sachusetts



March 13, 1928. 1,662,240

A. M. DRAKE INTERNAL GRINDING MACHINE Filed Feb.%'7. 1926 7 Sheets-Sheet 1 March 13, 1928. 1,662,240

A. M. DRAKE INTERNAL GRINDING MACHINE Filed Feb.27. 1926 7 Sheets-Sheet' 2 March 13, 1928. 1,662,240

A. M. DRAKE INTERNAL GRINDING MACHINE Filed Feb. 27. 1926 7 Sheets-Sheet 5 March 13, 1928. 1,662,240

' A. M. DRAKE I INTERNAL GRINDING MACHIN E Filed Feb. 27. 1926 '7 Sheets-Sheet 4 7 WQM March 13, 1928.

A. M. DRAKE INTERNAL GRINDING MACHINE Filed Feb. 27. 1926 7 Sheets-Sheet 5 March 13, 1928. 1,662,240

A. M. DRAKE INTERNAL GRINDING MACHINE Filed Feb.27. 1% =7 Sheets-Sheet 6 March 13, 1928.

- A. M. DRAKE INTERNAL GRINDING MACHINE Filed Feb. 27. 1926 Z Sheets-Sheet 7 Patented Mar. 13, 1928.

UNITED STATES (PATENT OFFICE.

ALDEN M. DRAKE, OF GREENFIELD, MASSACHUSETTS, ASSIGNOR TO GREENFIELD TAP & DIE CORPORATION, OF GREENFIEL'D,

SACHUSETTS.

Application filed February This invention relates to a machine for grinding internal surfaces and particularly to a machine of this type in which provision is made for gauging the work during the grinding operation.

.In the usual type of internal grinding machines, the grinding wheel enters the work from the outer or open side thereof and much time is lost through the necessity of running back the grinding wheel away from the work head, to permit inspection removal or replacement of the work. If the machine is provided with a size indicating device, it is also usually necessary to remove the size indicating device from operative position when the work is to be removed or replaced.

It is the general object of my invention to provide an improved grinding machine in which the work is unobstructed at its outer side, so that it may be freely removed and replaced without displacement of either the grinding wheel or the size, indicating device from operative position.

In the preferred form of my invention I accomplish this most desirable result by supporting the work upon a large hollow spindle and by presenting the wheel and size indicating device through the hollow spindle at the rear end of the work.

Another object of my invention is to provicle a wheel truing device operative upon the wheel as it is withdrawn within the hollow spindle. The wheel, the size indicating device and the wheel truing device are all housed within the spindle and are protected from injury thereby when the work is removed or replaced.

My improved machine also embodies ar-' rangements and combinations of parts having many other important advantages, as will be hereinafter described and more particularly set forth in the appended claims.

A preferred form of the invention is shown in the drawings in which Fig. 1 is a front elevation of my improved machine;

Fig. 2' is a left hand end elevation thereof, looking in the direction of the arrow 2 in Fig. l;

Fig. 3 is a rear elevation thereof, looking in the direction of the arrow 3 in Fig. 2;

Fig. 4L is right hand end elevation therelvIASSACHUSETTS, A CORPORATION OF MAS- INTERNAL-GRINDING MACHINE.

27, 1926. Serial No. 91,298.

of, looking in the direction of the arrow 4 in Fig. 1; a i

Fig. 5 is a partial sectional end elevation, taken along the line 55 in Fig. 1;

Fig. 6 is a sectional view of the parts shown in Fig. 5, taken along the line 66 in Fig. 5; and

, Figs. 7 and 8 are front and rear longitudinal sectional elevations taken along the iines7 7 and 88 in Fig. 5 respectively.

Referring to the drawings I have shown an internal grinding machine having a base 10, supporting a work table 11 (Fig. 4:) slidable on guidcways 12 and 13 on the upper part of the base 10. A work spindle 16 (Fig. 6) is mounted in an annular bearing 17 in a spindle head 18, secured to the work table 11. The work spindle 16 is of unusual large diameter and is provided with a large axial cylindrical opening 20 through which grinding wheel V, a size indicating device Sand a truing device T may be presented in operative position.

The work K is secured to the outer face or flange of the spindle 16 by any suitable work holding device or chuck. In the drawings, I have indicated jaws 21, secured by bolts 22, but these jaws are merely illustrative and in actual operation may be re placed by any other suitable form of workholding chuck.

Won]; drive.

The work spindle 16 is preferably provided with a driving pulley 23 through which the spindle may be rotated by a belt 24 (Fig. 4) from a wide pulley or drum 25 on a counter shaft 26. A small pulley 27 on the counter shaft 26 is connected by a belt 28 to a larger driving pulley 29 loose on a rear counter shaft 30.

A pinion 31 fast on the shaft is engaged by a gear 32 on a shaft which is preferably connected by a pulley 34, belt 35, and pulley 36 to the armature or driving shaft 37 of an electric motor M or other available source of power.

A friction clutch 38 is provided between the pulley 29 and the counter shaft 30. An operating handle 39 for the clutch 38 permits the work spindle to be. started and stopped as desired independently, while other rotating parts continue in operation.

A grinding wheel W (Fig. 6) is mounted. on a wheel shaft 10 having a bearing 41 supported in a wheel head 42 (Fig.- 1) slidable transversely on ways l3 and 441: formed on an arch-shaped support (Fig. 2), carried by. the base 10 and extending above and across therear end of the work table 11.

lV/LeeZ drive The wheel spindle at its left hand or rear end is provided with a pulley 46 (Fi 2) whichis connected by a belti7 to a driving pullcy' l8 on a counter shaft 49. A pulley 50 (Fig. 8) on the counter shaft 49 is connected by a belt 51 is, a pulley 52 on the motor shaft 37, previously described. A

guide pulley 53 (F 2-) is mounted on a versely, the hand wheel being connected to the table by suitable gearing not shown. Any suitableautomatic cross feedniechanism may also be provided, such as is in common use in internal grinding machines.

lVOrlc table dries.

The work table 11 is preferably reciprocated longitudinally by suitable hydraulic actuating mechanism which may be of the general type shown in the British patent to Marks, No. 200.853, dated July18, 1923. Certain parts of this operative mechanism are indicated in Fig. 1, in which I have shown a main valve casing and an auxiliary valve casing 61. The main valve (not shown) is slidablein the casing 60 and is provided with a. valve stem 62, to which is pivotally connected a handle 63 by which the main valve may be controlled manually. The same handlef63 is connected through a lever 64 to a valve rod 65 by which the rate of table travel maybe increased as desired.

Auxiliary valves are mounted in'the valve 7 casing 61 and are provided with valve stems 66 and 67. positioned for engagement by dogs 68 and 69 adjustable in a guideway 70 on the table 11.

13y. suitably adjusting thedogs 68 and 69, the hydraulic mechanism may be set to reciprocate the table 11 between any desired limits. The hydraulic table operating mechanism forms no part of. my present invention, and any other suitable operating mechanism-may be substituted therefor.

Reference to Fig. '6 will show that'the bearing 41 for the "wheel shaft 40 extends well within the opening 20 in the .work spindle 16,-sothat the wheel snaft has :1

the size indicatingdevice S and the: wheel truing device T.

I Size dedicating device.

I will now describe the construction and operation of my improved size indicating device, as best shown in Figs. 5, 6 and 8.

A cross slide 70 is mounted on guideways 71 (Fig. I8) formed on a stand 72, secured by screws 73 to the work spindle head 18. A block 74 is secured by a screw 75 to the cross slide 70 and is provided with ratchet teeth 76, engaged by a pinion 77 on the lower end of a short vertical shaft 78 (Fig. 5) having a small hand wheel or thumb nut 79 its upper end. The bearing 80 for the shaft 78 is preferably split in its upper portionv and is provided with'a clamping screw 81 by which the shaft 78 may be held from rotation. The cross slide 70 may thus be tLQlJUSlZQCl in its guideways 71 toward or from the work.

An offset arm 82 is formed at the inner end of the crossslide 70 and projects laterally therefrom and longitudinally of the opening 20 in the worlcsp-indle 16. The arm 82is preferably of a hollow segmental structure, as indicated in Figs. 5, 6 and 8, and is provided with a cross bar 83 at its extreme front end portion, which cross bar provides a support for a contact lever 85. The lever 85 is pivotally mounted onthe cross bar 83'by flat springs 86'socurcd at right angles on the block 83 and also on a corresponding portion of the contact lever The contact point 86, preferably in the form of a diamond or a piece of hardened steel, is mounted on the short or forward end of the lever and the long arm 85 of said lever extends rearwardly through the as r loo

offset-arm 82 to the cross slide 70, where it I is engaged by a. rod or plunger 87, slidable ill the cross slide 70. At its front end the rod 87 engages a plungerBS, forming a part of a visible indicator 89 (Fig. 4.)

This indicator may be of any usual com mercial form and'the details of construction form nopart of my' invention. It is suili cient to state that longitudinal movement of the rod 87 will cause thepointer of the" indicator to rotate, and register a corresponding position of the contact point 86'.

The indicator preferably contains a spring (not shown) which acts through the plunger 87 to hold the contact point against the work.

7 It willbe seen by reference to Fig.6 that the grinding wheel V operates uponthe work Kat a rertain point in the internal periphery thereof, while the Contact point 86 engages the surface being ground. at a point substantially diametrically removed from the point of wheel contact. The contact point 86 is mounted for axial movement with the work head 18 and has no axial movement relative to the Work K. Consequently the point 86 remain in operative relation with the work during the reciprocation of the work back and forth past the wheel W.

Operation.

- In setting up the machine, a piece of work K having a hole of standard size may be placed in the chuck and the cross slide may then be adjusted by the handle 79 to bring the pointer of the indicator to a zero line, when the contact point 86 engages the standard size hole in the work. The slide 70 is then clamped in adjusted position and the indicator will thereafter indicate the zero reading when'the work is ground to the desired size.

The short length and large diameter of the work spindle is of great advantage as any slight inaccuracies in the bearing are hardly perceptible in the reduced size of the work. The bearing 17 is preferably of the ball bean ing type, adapted'tocause thespindle to rotate very accurately and also to hold the spindle from'axial movement in either direction.

A front flange portion 16 of the spindle 16 may be provided with concentric rings 90 (Fig. 6) engaging corresponding grooves 91 in a ring 92, secured to the head 18. These flanges and rings are provided to prevent the entrance of abrasive to the bearing supporting the spindle.

Tming device.

The wheel truing device is supported in a manner quite similar to that of the size indieating device, and comprises a cross'slide 93 (Fig. 6) slidable in guideways 94 (Fig.7) and provided with a rack block 95 (Fig. 5) which engages a pinion 96 on a vertical shaft 97, supported in a split hearing 98, and provided with a hand wheel or thumb nut 99 and a clamping screw 100, all as previously described for the size indicating device.

The offset arm 101 of the crossslide 93 is formed in the shape of a rectangular open structure, with a cross bar 102 at its forward end, in which is mounted a wheel dressing tool or diamond. point 103 (Fig. The tool 103 may be secured in position by a binding screw 104 (Fig. 6) and engages the wheel W as it is withdrawn from the work K. The tool is adjusted toward and from the wheel W by the hand wheel 99 to dress the cylindrical surface of the wheel as often as may be necessary.

Additional clamping screws 105 and 106 (Figs. 7 and 8) are provided for binding the cross slides 70 and 93 more firmly in their guideways 71 and 94 and lock nuts 10? are provided for the screws 105 and 106.

General cud vantages.

Having described the details of construe tion and the method of operation of my improved grinding machine, the important advantages thereof will be easily understood.

The Work supporting face of the spindle 16 is entirely open and unobstructed, so that the work can be secured to the spindle or re moved therefrom without interference by the grinding wheel, the size indicating device, or the truing device.

This is an extremely important advantage, as the time of operation is very materially reduced by the fact that it is unnecessary to run the work back away from the wheel after a piece of work is finished. The work travel is stopped with the wheel merely withdrawn into the work spindle just suflicient to clear the work, after which the work may be immediately removed and replaced.

This construction not only reduces the time of operation, but also permits me to greatly simplify the machine by omitting the special attachments heretofore provided for taking care of the outward, idle run necessary to separate the work fromthe wheel and also necessary for swinging the indicator or truing device away from the face of the work.

M improved construction also reduces the cost y enabling me to use a very much shorter and more compact machine, as only a very short table travel is necessary.

Furthermore the large size and compact construction of the work spindle and drive is of very great advantage and much increases the accuracy of the work produced by the machine.

Having thus described my invention and the advantages thereof, I do not wishto be limited to the details herein disclosed other wise than as set forth in the claims but what I do claim is a 1. An internal grinding machine comprising a frame, a work supporting spindle having a relatively large axial opening therethrough, said spindle being adapted to receive and support a piece of work at the front end thereof having a cylindrical opening aligned with said. spindle opening and of less internal diameter, a hearing supportfor said spindle, a grinding wheel, a wheel shaft, a wheel head mounted on said frame at the rear of said work spindle with said wheel shaft projecting into said axial opening and said wheel adapted to enter and leave the work from the rear side thereof, means to cause relative axial movement of the wheel and work, and a size indicating device also extending through said spindle into the work from the rear and effective to give an indication of the internal diameter of the work during the grinding operation, the axial support of the work spindle and is movable thereon toward and from the. axis of the work. 7

3; The combination in a grinding machine as set forth in claim 1, in which the size- ,indicat-ing device is mounted on the bearing support of the work spindle and is movable thereon toward and from the axis of the work, and in which manual meansis provided for thus moving said indicating device.

4. The combination in a grinding machine as set forth in claim 1, in which the size indicating device is mounted on the bearing support of the work spindle and is movable thereon toward and from the axis of the work, and in which manual means provided for thus moving said indicating device and for clamping said indicating device in adjusted position. 7

5. An internal grinding machine comprising a frame, a work supporting spindle having a relatively large axial opening therethrough, a bearing support for said spindle, a grinding wheel, a wheel shaft, a wheel head mounted :on said frame at the rear of said work spindle with said wheel shaft projecting into said axial opening and said wheel adapted to enter and leave the work from the rear side thereof, means to cause relative axial movement of the wheel and work, a cross slide mounted on said work spindle bearing support for movement toward and from the axis of the work, said cross slide having an arm extending into said spindle opening from the rear and'alongside the wheel shaft to the front portion of. said opening, and a size indicating device pivotally mounted on said arm at the front end thereof andadjacent the work and effective to engage the work and indicate the size thereof during the grinding operation, the axial opening through the spindle being of a size sufficiently large to freely receive said grinding wheel and indicating device, said spindle having jaws or other work supporting devices projecting across said opening and adapted to receive a piece of work relatively smaller than said opening.

6; The combination in a grinding machine as set forth in claim 5, .in which a visible indicator is mounted on a part ofsa-id cross slide which projects outside of said spindle, and in which operative connections are provided from said pivoted indicating device to said visible indicator.

' 7. An internal grinding machine having, in combination, a work supporting spindle having an axial opening of substantial, diamg inding wheel.

etensaid spindle being adapted to receive and, support apiece of work at the front. end thereof having a cylindricalopening aligned with said spindle opening and ofles's' internal diameter, a grinding wheel shaft rotatable. in said spindle opening, a grinding wheel mounted on said shaft and adapted to enter the -work fromwthe rear, means to cause relative axial and transverse movement of the wheel and work, and means operable through said hollow spindle to enter the work from the rear, means to cause relative axial and transverse ,movement of the wheel and 'work, means to drive said wheel shaft att-he :rearv of said work spindle, and means operable through said spindle to gauge the Work diameter, the axial opening through the spindle being of; a size sufiiciently large to freely receive said grinding wheel and gauge means. 1

:9. An internal grinding "machine having, in combination, a work-supporting spindle having an axial opening ofsnbstantial diameter, said spindle being adapted to; receive and support a piece of work at the front end thereof having a cylindrical opening aligned with said spindle opening and of less internal diameter, a grinding wheel. shaft rotatable in said spindle opening, agrinding wheel mounted on said shaft and adapted to enter the work from the rear, means to cause relative axial and transverse movement of the wheel and work, and a Wheel truing device entering the work from the rear and effective to true the wheel while the grinding wheel'remains within said spindle opening, the axial openi'ng'through the spindle being of a size sufficiently large to freely receive said grinding wheel and truing means.

10. The combination in a grinding machine as set forth in claim 9, in which the truing device extends alongside the wheel shaft in said axial spindle opening.

11. The combination in a grinding -ma-' chine as set forth in claim 9, in which the truing device engages the wheel at a point on, the same side of the wheel axis as the point of engagement of the work by the v 12. The combination in a grinding ma chine-as setforth-in claim 9, in which the truing device extends alongside said wheel shaft in said axial opening, and in which means is provided for manually adjusting said truing device toward and from the axis of the work.

13. An internal grinding machine having, in combination, a work supporting spindle having an axial opening of substantial db ameter, said spindle being adapted to receive and support a piece of work at the front end thereof having a cylindrical opening aligned with said spindle opening and of less internal diameter, a grinding wheel shaft rotatable in said spindle opening, a grinding wheel mounted on said shaft and adapted to enter the work from the rear, means to relatively adjust the wheel and. work both axially and transversely, and means positioned within said spindle opening effective to true the wheel as it is withdrawn rearward from the work, the axial opening through the spindle being of a size sufliciently largeto freely receive said grinding Wheel and said truing means.

14. The combination in a' grinding machine as set forth in claim 13, in which manual means is provided for adjusting the truing device toward and from the grinding wheel.

15. An internal grinding machine having, in combination, a work supporting spindle having an axial opening of substantial diameter, said spindle being adapted to receive and support a piece of work at the front end thereof having a cylindrical opening aligned with said spindle opening and of less internal diameter, a grinding wheel shaft rotatable in said spindle opening, grinding wheel mounted on said shaft and adapted to enter the work from the rear, means to relatively adjust the wheel and work both axially and transversely, means operable through said hollow spindle to gauge the work diameter, and means to true the wheel as it is relatively separated rearward from the work, the internal diameter of said spindle being of a size sufiiciently large to freely house said grinding wheel shaft, grinding wheel, gauge means and truing means.

16. An internal grinding machine having in combination, a work supporting member having an axial opening, an annular bearing surrounding and rotatably supporting said member, said member being adapted to re ceive and support a piece of work at the front end thereof having a cylindrical opcning aligned with said axial opening and of less internal diameter, a grinding wheel, a wheel shaft therefor projecting into the opening in said supporting member from the rear end thereof, independent means to mount said shaft for rotary and axial move ment so that the open rear portion of the Work supporting member may be accessible without dismounting the grinder, and means to cause relative axial reciprocation of the wheel and work, thereby causing the wheel to enter and leave the work from the rear side thereof, the opening in said work sup porting member being of relatively large diameter, and the annular bearing of said member being of less axial length between the end limits of said bearing than the diameter of said opening.

17. An internal grinding machine having in combination, a work supporting member having an axial opening, an annular bearing surrounding and rotatably supporting said member, said member being adapted to receive and support a piece of work at the front end thereof having a cylindrical opening aligned with said axial opening and of less internal diameter, a grinding wheel, a wheel shaft therefor projecting into the opening in said supporting member from the rear end thereof, independent means to mount said shaft for rotary and axial movement so that the rear portion of the work supporting member may be accessible without dismounting the grinder, and means to cause relative axial reciprocation of the wheel and work, thereby causing the wheel to enter and leave the work from the rear side thereof, the opening in said wor sup porting member being of relatively large diameter, and the annular bearing of said member being of less axial length between the end limits of said bearing than the diameter of said opening, and said bearing being positioned closely adjacent the work.

In testimony whereof I have hereunto afiixed my signature.

ALDEN M. DRAKE. 

